This disclosure relates to a distribution boom for stationary or mobile viscous material pumps, comprising at least one boom arm having a box profile, which boom arm has two spaced apart side walls connected to each other by means of two spaced apart transverse walls, and comprising a conveying line, which is guided along the at least one boom arm and is fastened thereto, wherein each side wall of the boom arm has a lead-through opening for the conveying line.
A concrete distributing boom for stationary and mobile concrete pumps of this type is known (U.S. Publication No. 2015/0136266 A1). There the boom arms are configured, primarily for weight reasons, as a box profile. Guided in a regular manner along such a distribution boom is a conveying line, with which liquid concrete is conducted as viscous material to a remote location reached by the boom tip. In many specific applications, it is here necessary that the conveying line crosses the boom arm. This can be realized by guiding the conveying line past the boom arm, which is complex, however, in terms of design. In addition, it is known to provide the boom arm with lead-through openings on its two mutually opposite side walls and to guide the conveying line through the lead-through openings. In order to prevent rainwater from making its way inside the boom arm, a tube is guided through the lead-through openings, which tube receives the conveying line and, protruding on both sides of the boom arm, is fixedly welded to the side walls by means of a fillet weld seam. The making of a fillet weld is complex. Due to the size of a typical boom arm, the weld seam has to be made by hand, which increases the production cost.